(i) Technical Field
The present invention relates to a belt meandering correction apparatus and an image forming apparatus employing the same.
(ii) Related Art
In the related art, in some of image forming apparatuses like those described above, a plurality of image forming sections for forming toner images of mutually different colors are arranged in parallel to each other, and then the toner images of mutually different colors formed by the plurality of image forming sections are transferred an stacked directly onto a recording paper sheet conveyed in a state of being attracted to a paper conveyance belt extended around a plurality of rolls. Alternatively, the toner images are primary-transferred and stacked onto an intermediate transfer belt extended around a plurality of rolls, and then secondary-transferred collectively onto a recording paper sheet. As a result, an image of full color or the like is formed.
Further, in some of the above-mentioned image forming apparatuses, in a fixing unit for fixing a not-yet-fixed toner image transferred on a recording paper sheet, a fixing belt extended around a plurality of rolls heats and pressurizes the recording paper sheet on which a not-yet-fixed toner image is transferred, so that fixing processing is achieved.
As such, in some of the above-mentioned image forming apparatuses, in performing image formation operation, belt driving apparatuses are widely employed for driving the circulation of an endless-shaped belt member such as a paper conveyance belt, an intermediate transfer belt, a heating belt, and a pressurizing belt extended around a plurality of rolls.
Meanwhile, in the above-mentioned belt driving apparatuses, the endless-shaped belt member is extended around a plurality of rolls, and then the endless-shaped belt member is revolved by the drive roll so that the circulation movement of the endless-shaped belt member is achieved.
Thus, in the above-mentioned belt driving apparatuses, as known widely, a positional error and an insufficient component precision in the rolls for extending the endless-shaped belt member as well as variation or the like in the belt extending force and the driving force for the endless-shaped belt member cause a so-called meandering phenomena that the circulating drive is performed in a state that the endless-shaped belt member is deviated toward one end part in an axial direction of a roll. Then, the meandering phenomena in the endless-shaped belt member causes positional deviation in the recording paper conveyed by the paper conveyance belt, the toner image primary-transferred on the intermediate transfer belt, or the recording paper that undergoes fixing processing by the heating belt and the pressurizing belt. This causes color image deviation, image deviation, and poor fixing.